For almost three hours on Sunday evening the final of the 2014 World Championship dozed off under the warm lights of the Crucible Theatre. That is how long it took for Ronnie O'Sullivan and Mark Selby to play the first five frames of the second session of their best-of-35 final.

Selby, as if exhausted by his efforts in reaching the final, his first for seven years, burned as slowly as a church candle. And even O'Sullivan, the Rocket himself, going for his sixth world title, struggled to get off the ground.

But then, gloriously, O'Sullivan cast aside the dull clothes of his disguise and revealed his true self. It was as if he had become frustrated by Selby's ponderous tactical game, even though he had shown a commendable restraint one would not have seen a few years ago.

In the sixth frame of the evening he sunk a magnificent long red and careered on his way to a 131 clearance to extend his lead in the match to 9-5. For the first time in the session he had truly imposed himself on his opponent.

The momentum and adrenaline carried over into the next frame. O'Sullivan rattled in a break of 87 to leave Selby dejectedly planted in his seat. That made it 10-5 with two to play.

But when O'Sullivan missed a black off the spot in the next frame, Selby responded to reduce his arrears to four frames at 10-6. And, off form most of the day, he was delighted to make it 10-7 in the last frame of the night with a break of 62 which, remarkably, was his best of the match.

O'Sullivan, who had won the afternoon session 5-3, took the first frame of the evening, a scrappy affair in which both players had a number of chances. In the second O'Sullivan went ahead 57-0. Selby replied with a 42 before he got a double-kiss on the green to hand the initiative to O'Sullivan. In the next frame Selby started positively before jawing a red when looking well set and finally conceded to make it 8-3 to the champion, O'Sullivan.

Then Selby quarried out a break of 55 to win 82-25 and make it 8-4. O'Sullivan should have reinstated his five-frame advantage straightaway but in potting a red he also downed the green. Selby cleaned up for 8-5. And that was when O'Sullivan decided he had had enough.

He had threatened to run away with the opening afternoon session before Selby worked his way into the match by taking three of the next four frames. It should have been all four to level the scores after fluking the last red of the final frame. But then he missed the black to hand O'Sullivan the frame and the session.

It was a disappointment for Selby but he could scarcely complain. With breaks of 69, 102 and 63 later on O'Sullivan looked the form player against an initially nervous looking Selby, whose best score was 38 in the opening eight frames. It appeared that Selby was suffering a hangover from his marathon, 12-hour 17-15 semi-final victory over Neil Robertson on Saturday – O'Sullivan had had the day off after demolishing Barry Hawkins 17-7 with a session to spare.